The Hungarian National Cancer Registry (HNCR) was legally established as a population-based cancer registry in 1999, and its operation started in 2000 supporting the planning and development of the Hungarian oncology network as well as informing national cancer control policies. Ensuring comparable, accurate, and complete data on malignant and in situ neoplasms is critical in determining the applicability of the database. The aim of this study was to perform a comprehensive evaluation of the data quality at the HNCR.
Based on qualitative and semiquantitative methods from current international guidelines, we assess the comparability, completeness, validity, and timeliness of the collected data over the diagnostic period 2000–2019, with a focus on the year 2018.
Coding practices and the classification system used at the HNCR are based on the International Classification of Diseases (ICD-10), which differs from the internationally recommended ICD-O. The annual trends in incidence did not indicate major fluctuations, that may have resulted from data collection discrepancies, while comparisons of the mortality-to-incidence ratio (M:I) compared with 1 minus 5-year observed survival indicated some systematic differences requiring further exploration. The age-standardized (European standard) incidence rate per 100 000 measured by the HNCR in 2018 was very high: 647.9 for men and 501.6 for women, 11.6% and 14.6% higher than the International Agency for Research on Cancer (IARC) estimates respectively. Behind the overall differences between the two data sources, we identified that the vast majority were due to ill-defined ICD codes: malignant neoplasm of other and ill-defined sites (C76), and malignant neoplasm without specification of site (C80). Otherwise, there were no major discrepancies by localization. The proportion of morphologically verified cancer cases was 57.8% overall, that of death certificates was 2.3%, and that of unknown primary tumors was 1.4%.
Further implementations and interventions are required to ensure that the operations, coding practices, and the classification system used at the national registry are in accordance with international standards, and to increase the completeness and validity of the collected cancer data. In particular, the low morphologically verified proportion questions the overall accuracy of the stated diagnoses within the database. Nevertheless, our examination implies that the data of the HNCR are reasonably comparable, and without doubt fulfill the requirements to support national oncology services and cancer planning. However, most importantly, a review of registry personnel and resource requirements to run the national population-based cancer registry should be an essential part of Hungary’s national cancer strategy.
- • The HNCR commenced population-based activities according to international standards in 2000 to support national oncology services and cancer planning.
- • We assessed comparability, completeness, validity and timeliness of the most recent cancer data in Hungary according to international guidelines.
- • Behind the overall differences between the HNCR measured figures and IARC estimates we found no major discrepancies by site, only in case of the ill-defined sites. However the Registry contains a subset of unverified and miscoded data.
According to the estimates of the Global Cancer Observatory (GLOBOCAN), Hungary has among the highest all-cancer incidence rates in the world (321.6), which highlights the necessity for a population-based cancer registry . The Hungarian National Cancer Registry (HNCR) has operated from the 1950s, although its legal basis was established only in 1999. In that year a regulation order of the Ministry of Health authorized national cancer registration to commence at the National Institute of Oncology (NIO) to support national oncology services and cancer planning. Population-based activities launched in 2000, and the HNCR has published annual cancer statistics covering the whole of Hungary thereafter , apart from childhood tumors, which are collected by a specialized registry . However, local hospital-based data collections on cancer diseases were present in Szabolcs-Szatmár-Bereg and Vas counties and in the city of Miskolc much earlier (from the 1960s). Since their ceased operation, Hungary has not been represented in the ‘Cancer incidence in five continents’ series since 1987 . According to the 2001 census, the population of the country was 10.2 million, which decreased to 9.8 million by 2019, with males and females comprising 47.8% and 52.2%, respectively, in the latter year . Data transmission is a legal obligation across all 142 healthcare providers in the country, regardless of whether they are private or public institutions. In Hungary, most healthcare costs are financed by the National Health Insurance Fund that covers the whole population. The organization of the state healthcare system is pyramidal, comprising basic care, outpatient specialists, general hospitals, and regional centers. The latter comprise medical universities and national institutes, for which the NIO is the only organization that focuses exclusively on cancer.
Given their key role in cancer control, population-based cancer registries should be able to provide an objective evaluation of the quality of the data collected . With the HNCR playing an increasingly significant role in monitoring the cancer situation in Hungary, we provide the first evaluation of the comparability, completeness, and validity of recent data at the HNCR. Applying the principles and techniques of evaluation described in international guidelines , and their practical implementation , we provide an overview of data quality at the HNCR in the context of future plans for the registry.